Question

which structure is highlighted?
hair shaft
hair papilla
hair follicle
hair root

Explanation:

The hair follicle is the structure in the skin from which hair grows. The hair shaft is the visible part above the skin, the hair papilla is at the base of the follicle with blood - vessels, and the hair root is the part below the skin within the follicle. The highlighted structure is the hair follicle which encompasses the root and provides nourishment and support for hair growth.

Answer:

hair follicle